The present invention relates to an instrument to measure the quantity of liquid obtained in a novel adsorbent/absorbent material used in association with packaging systems and/or a cleaning pad for industrial and medical applications.
Prior attempts to control leaking materials have been disclosed in U.S. Pat. No. 4,749,600 (Inventors: Cullen et al.). Cullen et al. disclose a packet for absorbing and immobilizing a liquid. The packet looks like a sugar packet (See FIG. 3 of the xe2x80x2600 patent) by having an outer layer and inner contents. When the packet is to be used, it is inserted within an outer container, like a Federal Express package. In most instances, the packet falls to the bottom edge, in particular a corner, of the outer container. See Col. 2, lines 46 of the xe2x80x2600 patent. Along with the packet, an inner container of a liquid, like a test-tube of blood (See FIG. 5 of the xe2x80x2600 patent) is inserted into the outer container. According to the xe2x80x2600 patent, the bottom edge of the inner container should contact the packet. Thus, when the blood spills from the inner container, the blood may contact the packet.
If the blood contacts the packet, the blood dissolves the outer layer. The packet has an inner layer of polyvinyl acetate and an outer layer of starch paper or any other liquid-degradable material. The polyvinyl acetate has to be the inner layer in order for the packet to be formed. See col 2, lines 9-11 of the xe2x80x2600 patent.
When the outer layer dissolves, the inner contents are released and form a gel-like substance by absorbing the blood. The inner content is sodium polyacrylate having the formula (C3H3O2Na)n. It is obtainable under the trademark WATER LOCK J-550 from Grain Processing Corporation.
A problem with the Cullen et al. attempt to. immobilize a liquid, is that the packet is so small that it is possible that the liquid may never contact the packet. For example, if the packet is located at the bottom of the outer container, as Cullen et al. suggest, and the liquid leaks to the top of the outer container, the packet will never immobilize the liquid since the liquid never contacts the packet. Thereby, the liquid spills from the outer container and provides little protection to the handler of the package. These results could be extremely deleterious to the handler. For example, if the liquid is HIV contaminated and that liquid contacts a cut on the handler, that handler could become infected. This problem is solved by the present invention.
A closer reference is U.S. Pat. No. 5,984,087, assigned to Technicor, Inc. -the owner of this application. In the xe2x80x2087 patent, the invention xe2x80x9crelates to a packaging container designed to transport an inner container containing a liquid. The packaging container has at least one sealing multi-layer comprising a first water soluble film and an absorbent material. The inner layer of the packaging container is the water-soluble film that forms the boundary between the cavity that hold the inner container and the packaging container. When the liquid leaks from the inner container while in the packaging container, the liquid dissolves the water-soluble film. When the film is dissolved, the absorbent material is released to absorb and immobilize the liquid material. This immobilization prevents the liquid from escaping from the packaging container.xe2x80x9d Abstract of the Invention. The present invention discloses another embodiment of that invention which was not fully disclosed in the xe2x80x2087 patent.
A problem with these systems was that it was difficult, if not impossible, to determine the amount of liquid that was obtained from the pad or container.
The present invention relates to a device for measuring the amount of liquid absorbed and/or adsorbed by a packaging unit, or cleaning pad, which is designed to absorb and/or adsorb liquid that is being transported and was spilled or released. The packaging unit or pad has at least one sealing multi-layer comprising a first water soluble film and an absorbent material or an adsorbent material (hereinafter referred to as xe2x80x9cabsorbent/adsorbent materialxe2x80x9d). When the liquid contacts the water soluble film, the liquid passes through the water-soluble film. When the liquid contacts the absorbent/adsorbent material, the absorbent/adsorbent material immobilizes the liquid material. This immobilization prevents the liquid from escaping from the absorbent/adsorbent material. The pad/packaging unit is then measured by the instant device to determine the amount of liquid obtained.